Test-guard for automatic switching apparatus.



N; REYNOLDS.

TEST GUARD FOR AUTOMATIC SWITCHING APPARATUS.

'l l fifi a APPLICATION FILED AUG. 18. 1913.

Patented Jan. 5, 1915.

w uwi A. v3 Rm 3 .ronn'n. sermons, on ennn'nwrcn, comvnbrircur, assrsnon 'ro Wnsrnnn nnncrnrc comm. or new YORK, N. Y., a conronarrou or ILLINOIS.

TEST-GUARD FOR AUTOMATIC SWITCHING- APPI'US.

trainee.

Specification of Letters Patent.

Pat nted ran a rare,

Application filed August is, rare. Serial no. tsetse.

To all whom it may concern;

Be it known that LJOHN N. 'RnrNoLDs, a citizen-of the United States, residing at Greenwich in the county of lfiairfield and State of donnecticut, have invented a certain new and useful Improvement in Test- Guards for Automatic Switching Apparatus, of which the following is a full, clear, concise andexact description.

This invention relates to telephone exchange systems of the automatic andsemiautornatic type in which the selection of lines or trunks forthe extension oftelephone circuits is accomplished by mechanical selector switches andmeans whereby a plurality or group of such switches may he drivenfrom a common source of power or master mechanism. a

The principal feature of this invention resides in means whereby each line will be caused to test busy While in use, and Whereby all lines of 'a group will becaused to test busy during the period that; the master mechanism is in use:

lhe drawing is a diagrammatic illustra tion of the apparatus and circuits comprising any invention. s

The mechanism .shovvnin the drawingis substantially the same as that disclosed in latent No. L020,185. It is otthe master and individual type of mechanism arranged to be operated 'on' What is lmovvn. as the panel form of selector multiple. :lhis multiple consists preferably of strips off-metal having contact points spaced at regular in.- tervals along their entire length. These strips are placed one upon another with strips of insulating" material hettveen in such a manner as to form vertical banks of contacts over which the selector contact brushes can be moved in a vertical direc tion, each vertical hank of contacts forming the cooperating terminals of a separate selector. The banks may comprise any desired number or: sets of contacts and the selector multiple g-rnay comprise as many multiple banks asniay be conveniently used. As herein described, each loanir is considered as accommodating contacts forming the transmission and test terminals of 100 lines,

but it should he understood that this invention is not limited to such construction.

in the drawings a part of a bank of contacts as referred to above is indicated gen orally at 84:. The set ct contacts 85, 86 and 87 form, respectively, the transmission and test terminals of the line 35? 855 and 356 to a further selector. The brush carrier 88 carries the brushes 89 and 90 arranged to contact respectively with the terminals 85 and 86', and the brushes 91 arranged to contact with the test terminal 87. This brush carrier is carried by a metallic tape 92, passing around the sheave 76 of the driving mechanism individual to the selector and an idler pulley 8 at the top of the bank of terminals. 'lhis tape when moved by the rotution oi. the sheave 76 carries the brushes into position to make contact with the terminals 85, 86 and 87 of the desiredline, the selection losing determined by the extent ot the movement of the tape, the control of which will he hereinafter iully set forth. v

@Briezdy considered, selection is accomplished by moving the hrushes to the top of a group of terminals and then causing the brush carrier to be moved in the reversedn terminal-s until the desired set has heen reached. v

The driving" mechanism through which rection step by step over the sets oft-contact power is supplied for moving the brushes 89 and 91 on the hrush c'arrierfid into contact with the terminals $5 86 and 8'? comprises the master clutch mechanism 133' il -his sleeve 2i is free for longitudinal movement and upon energization or" the electromagnet 25, the dish 23 will be drawn into frictional engagement with the dish 19, whereby power will betransmitted to the pinion 22. The pinion 22 meshes with the Wheel 28 fined upon the shaft 29. Upon the shaftjQQ are also mounted the interrupters 33 and 34;, The interrupter 33 cooperates with the contacts. 35, 36 and serves to make and break the circuit between these contacts (ance tor every revolution of the shaft 29. Th win-,- utator 3t sinularly cooperates passes.

with the contacts 37, 38. to make andbrakf the circuit between thesecontacts at s ray revolution of the shaft 29. The relatiomnf the make andbreak of. the circuits between:

contacts 35 and 36, 37 and 38, respectively, will be hereinafter referred to.

The disk 39 whichis also mounted on the shaft'29 has coiiperating therewith the arm 40 mounted'upon the shaft 29 and held in definite relation to the disk 39 by the spring 41, which is fastened at its respective ends to the disk, and the arm.- This arm 40 cooperates with the armature 42 of the stop magnet 43 to stop the rotation of the disk 39 and likewise the shaft 29 when the mag net 43 has been deenergized. It, however, permits a slight overrun by the disk 39 due to the extension of the sp ings 41, which overrun willhe corrected and the disk 39 brought back into proper position by the contraction of the spring 41. The armature 42 whichisnormally in a retracted position,

due tothe tension of the retracting spring 46, operateswhen attracted for purposes hereinafter set forth to close the contacts 47 and 48.

Upon the shaft 29 arefixed at proper intervals the gearwheels 69 which transmit ppwer to the individual driving mechanlsms 14.

Individual dfim'ng mechanism.-The individual driving mechanism comprises the shaft 79, to one end of which is afiixed the gearwheel 71 which meshes with the gearwheel 69, above referred to, upon the main drivin shaft 29. Adjacent to the gearwheel71, and also fixed to the shaft to, is the disk 72 of soft iron, or other magnetic vmaterial, which forms the armature of the electromagnet 73, which when energized attracts the'disk 72 to move the shaft so that the clutch member 74. fixed on the other end of the shaft is moved into operative relation with the clutch member 7 5, fastened tothe sheave 76 around which the metallic tape 92 The shaft 70 is normally held in a position in'which the clutch member 74 is out of coiiperative relation with the-clutch member 75 by means of the spring 78.

The inner rim of the sheave 7 6 is made to form a ratchet by having out therein the.

teeth 7 9; Cooperating with theseteeth 79 is the armature 80 of the electromagnet 81, hy the energization of which the armatureis adapted to be attracted to remove the projecting piece 82.upon the armature 80 out of cooperative relation with the teeth 79. The

r the pro1ect1ng piece armature 80-is normally held retracted and held'in engagement with the teeth 79 by the spring 83.

The movement of the sheave 7 6, therefore,

7 depends upon the energization of the clutch magnet .73 and the rotation of the shaft 29.

i The shaft 29, however, having moved the sheave and tape into any given position,

'they maybe prevented from returning by -the projection 82 upon the armature 80 un- 'der the control of the release magnet 81.

. Sequence s-witch.-To control the local circuits at the various parts of the system, which local circuits must be established in definite order at successive'stages of the oporation, automatic switching appliances which are termed sequence switches are employed. A sequence switch 200is associated with the master driving mechanism and-a sequence switch is associated with .each individual driving mechanism as is indicated upon the drawings. These sequence switches each consist of a movable switch operating member, a number of circuit changes beingmade in sequence as said member is moved from one position to another. An electromagnet and a constantly rotating source of power, the connection of may be actuated, so that the sequence switch may again he automatically advanced to the next positi on in which a new set of circuits is established. v 1n the form of sequence switch mechanism shown diagrammatically on the drawings, 171 represents a constantly rotating shaft having at one end a disk 174 of brass or other non-magnetic material. Adjacent to the disk 174 is a disk-17 6 fixed on the shaft 177 and forming the armature of the clutch magnet 101.. This disk 176is formed of magnetic material.- Upon the energization' of the electromagnet 101 the disk 176 will be drawn into frictional contact with the disk 174 which is constantly rotating and the two disks will, therefore, rotate. to-' gather. I

lUpon the-shaft 177 is also fixed a gearwheel 181 which meshes with the gearwheel 182 fixed on a shaft 184. On this shaft 184 are fixed cam wheels made of insulation, upon the outer rim of which are formed cam surfaces which coiiperatewith the various contact springs represented in the drawing, to force such springs into and out gagement with their coiiperaiting contacts.

hastened upon one end of the'shaft 184 is a stop wheel 190 formed withfnotches upon its periphery in which the projection 191 upon the armature 192 of the, electromagnet 102 is mature is retracted to stop the rotation of the shaft promptly and accuratelv when the position desired has been reached and the electromagnet 102 has been deenergized.

of enadapted to rest when the ar-- too lit") a p nd ng; group o tru k nes! ly one trunk comprising conductors 303 and 304 being here.shown.-

We will now assume that the calling line has been connected through some well @ownmeanswith thebrushes 366, 367 and 368' of a selector 375 and that this Selector is caused in awell known manner to hunt for the, terminals of an; idle trunk. Associated with terminals as 310 and 311 the trunk conductors are the test terminals 312'. Associated with the test terminals 312 of each trunk is a double wound relay G, and the conductors 165 and 166 are common to all the relays G of a group of trunks.

As previously stated, the object of this,

invention is to provide meansnzhereby all the'test terminals of a group of trunks will 7 test busy while the master mechanism is in use, and further means whereby each trunk will test busy while a connection is established orbeing established thereover.

Assuming now that the brushes 366, 367 and 368 are passing over the terminals of a group of trunks, upon the brush 368 engaging the test contact 312 of the first trunk 2 line, if this trunk line is idle and: the master mechanism is not in use, a circuit will be completed from the battery 150,.through the resistance R, armature and back contact of the relay Gr associated with the first test con tact 312, brush 368 and test relay '1 to ground,

thus energizing the relay '1. and causing the selector to stop with the brushes on the terminals of this trunk. If, however, at a preceding instance, another selector 375 had com'eto rest on the test terminal of one of the trunks of the group, the potential of the test terminals would be reduced, as will presently appear, and insuficient current armature, and the brushes would passover all the test terminals of the group, unless the master mechanism became idle after having performed its part at setting up the preceding connection before the last test terminal oi the group. was reached, in which case, those of the group remaining to be passed over will he tested, and if an idle tru'nkis found, the brushes will come to reston the terminals thereof. The reason tor.

his wi l p e e tly m an Associated with the. conductors, terminating in the brushes 366. and 367 by any desired means are the leads 364, 365 extending to a, sender of the revertive impulse type.

A; circuit will now extend from battery 308,

be; actuated due to the high resistance ot' its left winding and to the resistance 305 in the circuit. Upon the attraction of the armature of stop relay 306, resistance 305 is short circuit/ed, increasing. the flow of current in the circuit just traced. Relay 314 will now become energized, completing a circuit from battery, through. armature and front Contact of relay 314, conductor 120, sequence switch contact 104 (0), sequence switch contact 105 (0), clutch magnet 101, stop magnet 102 to ground, whereupon the individual sequence switch 100 will move to position 1. .ln position 1 a circuit is completed from conductor 303, through sequence switch contact 106 (1), low resistance right winding of relay 314, sequence switch contact 107 (1),

' conductor 121, left winding of relay L, se-

Qunder the control of'its special contact 210.

As the sequence switch 200 reaches position 2, a

a circuit is completed from battery, through armature and front contact of relay L, sequence switch contact 205 (2), stop magnet 43 to ground. Magnet 43 becomes energized,

removingits armature 42 from engagement. with the arm .40. The attraction of the armature, 42 also causes engagement of the contacts 47 and 48, completing-a circuit from battery, through the master mechanism clutch magnet '25 and conductor 123, causing the shaft 29 and the drum 7 6 to rotate, the individual-clutch magnet having been previously energized through a circuit from battery, through sequence switch contact 111 (1). The gears'69 and 71 are of such proportions that each rotation of the shaft29 will carry the brushesof the selector over a group of terminals in the bank 84. Each revolution of the shaft 29 also causes, by' means of the interrupter disk 33 and the brushes 35 and 36, an interruption of the previously traced circuit through relay L, deenergizing the stepping magnet 307 the brushes.

circuit is opened, by the closure of aficircuit from battery 30, through brushes 37 and 38,-

metallic portion of the interrupter 34 and the right winding of relay L. Relay 314 remains energized during the periods the circuit through its right windingis interrupted,-as the flow of current through the left winding of this relay is sufiicient' to hold up its armature even though the armature of relay 306 may be retracted, thus'including the resistance 305 in the circuit, although insuiiicient to attract it. The opening of the circuit by the interrupter 33, as

just stated, caused the deenergization of the.

sender stepping relay 307. As the sha ft 29 continues to rotate, however, circuit is again completed through the metallic portion; of the interrupter 33 to again close the circuit,

and upon a slightly further rotation of the shaft, the local energizingcircuit of the selector relay L through tne right'winding thereof is opened bythe contacts 37 and 38 engaging the insulated portion of the interrupter disks 34.

If at this stage of the operation the short circuit about resistance 305 remains closed, the rotation of the shaft 29 and the consequentelevation of thebrush carrier will be continued until the brushes have passed over'another group of terminals. These operations will be repeated and the contact brushes caused to move upwardly over the groups of contact terminals until the repeated energization and deenergizatio'n of the sender stepping magnet causes the de energization of stop relay 306, thus including the resistance 305 in the sender circuit;

-,When. now the rotation of the shaft 29 has caused the opening of'the local energizing. circuit through the ri ht wi ding of relay .L, relay L will become deener zed, due to the inclusion of resistance 305 m its circuit,

* and its armature retracted, closing a circuit from, battery through sequence. switch contact 208 (2) clutch magnet 201 and stop magnet 202 of master sequence switch 200, causing the sequence switch to move "out of position 2 and back'to normal or zero position. As sequence switch- 200 moves out of position 2, itmomentarily closes sequence switch contact 209, completing a circuit from battery, .through contact 209 (29;), contact 109 (1), clutch magnet 101 and stop magnet 102- of the individual sequence switch 100, thus moving the sequence switch into position 2;

When the sequence switch reaches position is completed from battery 360,-

11 a circuit through resistance 359, conductor 35,6, contact 87, brushes 91, sequence switch contact closes a circuit to maintain the select 114 (11;) and test relay J to ground. If the contact 87 is the test terminal of an idle trunk, relay J will be energized and, inattracting its armature, will complete a momentary circuit from bgttery, through contact 112 (2), armature and front contact of relay J and magnets 101 and 102 of sequence switch 100, and causing said sequence switch to continue to position 3 or talking position, If, however, a selector is associated with the multiple terminals of this trunk, insufficient current will be-supplied to relay J to cause it to attract its armature, due to the shunt-circuit thereabout, through the corresponding test relay at the selector pre viously engaged with the terminals of the first trunk. Now in position 2 of thesequence switch, a circuit-is completed from battery,-through contact 112 (2), armature and back contact-of relay, J ,stop magnet 81, contact 113 (2) and interrupter 125 to ground. 'Magnet 81 will becomemomentarily energized,removing the pawl 82 from the ratchet teeth 7 9 and the brushes will be allowed to return one step into engagement with the next set of contacts. This energize.- tion, and deenergization of relay 81 will be repeated until brushes 91 engage a contact 87 associated with an idle trunk, when-relay- J will become energized, breaking the circuit just traced through the stop magnet 81 and stopping the movement of the brushes. The-attraction of the armature of relay J also completes the circuit'through clutch magnet 101 and 1 the sequence switch 100, whereupon thesequence switch will move into position 3, thus closing at contact-115 (3) and 116 (3), the conductors to the selector brushes 89 "and 90. The line will now be extended to 105 the 'next selector: When the sequence switch 100 passed from positio'n'2 to'position 3, it interrupted at contact 103 the holding tircuit for the line relay 314, but

simultaneously completed a circuit through 110 the rightwinding of saidv relayffrom battery? 360, through test'brushes' 91,-contact 107 (3'), right winding of relay 314, and-contact 106 "(3) to ground. a

Going back now means of which the trunk'consisting. of the conductors 303 and 304 was selected, it will- "be seen thatas soon as the master-sequence switch 200 reaches position 1, .a circuit is closed from battery, through sequence switch 2 contact 211,"co nductor 166, and-all the re' lays G in, series, whereby said relays, becoming energized, attract their armatures, thus removing battery 15 0 from all the-test termina1s-312 ofthe group of trunks being tested. Battery is now supplied to the test contact. 312 through the left winding, front contacts and armatures of the relays G, but is. of insufiicient potential, due to the-high resistance of this winding, to cause the ener:

stop magnet 102 of to the testing process by gization of the relay T as the test brush 368' passes over the test contacts 312. These relays will remain energized as long as the master mechanism is in use, but upon its return to normal, the contact 211 will be opened, thus deenergizing the relays G of all the idle trunks. The relays G of the busy trunks, however, will be maintained energized by a circuit from battery, through theleft windings of said relays, front contact and armature, test terminals 312,. brushes 368, and test relay T of the selector associated with said trunlr, this current being suificient to hold up the armatures of the relays '1 through the circuit then completed, although it is insufficient to cause their attraction. Thus it will be seen that means are provided which will cause all the trunks of a group to test busy while the master mechanism is employed, and whereby a trunk will test busy at all of its multiple terminals while a selector is associated therewith. When the brush carrier 88 starts to move upwardly, the 01? normal contact 344 is closed for a purpose to be hereinafter described. When disconnection is desired, the connection of battery 360 to conductors 356 is interrupted and relay 314 becomes deenergized, completing a circuit from battery, through armature and back contact of said relay, sequence switch contact 105 (3), clutch magnet 101 and stop magnet 102 of sequence switch 100, thus moving the se quence switch through position 4 to normal under the control of contact 105. .In position 4 a circuit is completed from battery, through contact 111 (4), off normal contact 344, stop magnet 81, contact 113 (4), to Y ground. Pawl 82 carried by the armature. 80 is thus retracted and the brush carrier 88' is returned to'its normal position by gravity or in any desired manner. Upon the return of the carriage to normal, the OE normal contact an is opened, thus interrupting the circuit for the stop relay 81 and completing,

the last movement necessaryto return all the selector apparatus to its normal posit1on.

What I claim is:

1. In a telephone exchange, a group of connecting circuits, sets of movable contacts in which said circuits terminate, a single motor means for individually moving saidsets of contacts, and means whereby all of said connecting circuits will be caused to test busy while said common motor means is in use.

-2. In a telephone exchange, a grou of connecting circuits, switch brushes in w ich said circuits terminate, a contact terminal at the Opposite end of each of said circuits, a common motor means for movin said brushes, and means whereby all of said circuit terminals wifi be caused to test busy while said motor means is in use.

' 3. In a telephone exchange, a group of connecting circuits, switches in which said the circuits ofsaid group will be caused to test busy.

4.111 'a telephone exchange, a group of circuits, brushes in which said circuits terminate at one end, a test contact associated with the opposite end of each of said circuits, a relay associated with each test contact for governing the potential thereof, a single motor means for moving said brushes, means whereby all of said relays will be energized while said motor means is in use, to cause said circuits to test busy.

5. In a telephone exchange, .a grou of connecting circuits, switch brushes in w ich said circults terminate, a single motor means forv independently gmoving said brushes,

means whereby all of'saidncircuits of said associated with the opposite ends of said T circuits respectively, a relay for each of ch said cirently movin said brushes, means for ener- 'gizing all 0 said relays while said motor mechanism is in use, and means for thereafter maintaining energized such of said relays as are associated with the test terminals of busy connecting circuits as'long as said circuits are employed.

In witness whereof, I hereunto subscribe 12a my name this 15th day of August. A.D.

JOHN N. REYNOLDS. Witnesses: I

MURRAY V. CONATY,

' Howano J. Dawns.

100 said test terminals for altering the potential v 

